The overall objective of this grant application is to continue the investigation of a large cohort (N-2379) of black and white girls who were enrolled at age 9 and 10 in the NHLBI Growth and Health Study (NGHS) at three centers and followed longitudinally until age 13 and 14. This investigation will allow for follow-up through an important period of adolescence (age 14 - 16), the time in which racial differences in obesity become more pronounced, and to examine the association of obesity with cardiovascular risk factors. Since obesity-onset is associated with puberty, the additional follow-up is necessary to track the cohort through maturation. The dietary habits and patterns of physical activity; biological maturation, psychosocial and socioeconomic factors; and physiological factors of the two race groups will be investigated as factors contributing to the black-white differences in the development of obesity. The specific aims of the NHLBI Growth and Health Study Extension (NGHS II) are described in detail in the collaborative grant application.